1. Introduction
Abnormal lipid metabolism in obesity can impair insulin signaling by inhibiting the release of glucose from the liver and its uptake by the fat and muscle cells [1]. An overloaded long-term high-fat diet (HFD) leads to obesity, which can induce insulin resistance in many tissues such as the liver, skeletal muscle, and adipose tissues. In the insulin-resistant state, insulin is unable to inhibit lipolysis, which results in increased circulating free fatty acid (FFA) [2]. The elevated FFA levels increase the chronic hyperglycemia and hypertriglyceridemia. Hepatic insulin resistance can increase the hepatic gluconeogenesis and lipogenesis [3]. FFA accumulation in the liver results in hepatic steatosis and contributes towards dysfunctional insulin signaling [4]. Moreover, the adipose tissues in the obese state are largely expanded and function abnormally in the regulation of cytokine release as well as fatty acid metabolism and its storage [4].